Method of preparing dispersions of photographically useful compounds
US5753390A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1996 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Jul 17, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/136
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is described for preparing a concentrated dispersion of a photographically useful compound ready-for-use in coating solutions of hydrophilic colloid layers of a silver halide photographic material, wherein said compound has at least one ionisable acid site on its molecule, the said method comprising the steps of deprotonising and solubilising the said compound in alkaline medium; microprecipitating the said compound and milling the microprecipitated compound obtained, coating the said dispersion of a photographically useful compound in non-light-sensitive and/or light-sensitive hydrophilic layers of a silver halide photographic material, wherein milling proceeds during and/or after the microprecipitating step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.